Lithuania, would have its own state offices and participate in the Commonwealth's Sejm. The Eastern Orthodox Church was to be given equal rights with the Catholic Church, with Orthodox bishops seated in the Senate. Nobility status was to be granted to many better off Cossacks ("...so measured, however, that out of each regiment one hundred can be granted nobility"). But the Cossack register was limited to thirty thousand and with the allowed return of the Polish szlachta to their prewar possessions, many of the ordinary Cossack rebels would have been reduced to feudal peasantry status again. The treaty was reluctantly ratified by the Sejm in May 1659, however with the Cossack negotiated gains substantially reduced, which contributed to the pact's eventual demise, a rejection by the increasingly Moscow-influenced Cossack assembly in September. For the Cossack rank and file, what Vyhovsky had negotiated offered too little and came too late. The crucial factor that doomed the Hadiach treaty was that the sizable regular Ruthenian nobility (not magnates), which would constitute the principal Ukrainian elite with a strong interest in the establishment of the Duchy of Ruthenia, was after ten years of warfare physically eliminated almost in its entirety. The Treaty of Hadiach became also a major factor leading to the Commonwealth's renewed warfare with the Tsardom, which considered the accord a violation of the previously agreed truce. The approaching Russian army was defeated at Konotop in July 1659 by Vyhovsky with Polish and Tatar help. During disturbances among the Cossack masses that followed, Jerzy Niemirycz was killed. But Moscow's pressure continued and in the fall Ivan Vyhovsky was forced to give up his hetmanship and was replaced by Yurii Khmelnytsky, Bohdan's son. Khmelnytsky, in an attempt to preserve the unity of Ukraine (the left-bank Cossack regiments had already joined the Russian side), concluded a new Pereyaslav agreement with Russia on October 27. The articles substantially reduced the Ukrainian autonomy and the hetman's authority. The Kiev patriarch became a subordinate of the patriarch of Moscow. Russia's progressive incorporation of all of Ukraine was however prevented by the military developments that followed. Russian armies advanced in 1660. The Commonwealth mustered all its military resources and in Lithuania Stefan Czarniecki and Paweł Jan Sapieha defeated Ivan Khovansky at the Battle of Polonka. The Russians had to abandon the siege of Lachowicze (Lyakhavichy) and withdraw beyond the Berezina River. Vilnius was recovered by the Poles